<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <title>Document</title>
    <script src="./base/vue.js"></script>
</head>
<body>
    
    <div id="app">
        <p v-for="item in items">{{item}}</p>
    </div>
    <script>
        var vm = new Vue({
            el:"#app",
            data: {
                items: ['a', 'b', 'c']
            }
        })


        //vm.items[1] = 'x' // 不是响应性的
        Vue.set(vm.items, 1, "x")
    </script>
</body>
</html>